score and high score system for multiple levels

Question

I'm trying to create a scoring system for a game with multiple levels. For this I'm using the binary formatter instead of playerprefs (I read online that playerprefs are not that secure). I have created the system but whats happening is that the score is not resetting to 0 when I load a new level. If in one level the score was 10 and I start some other level, the score in this level starts from 10 instead of 0. This is the code I have so far:

public class ScoreIncrease : MonoBehaviour
{
  public Text scoreTxt;
  public int score;

void Start()
{
    LoadScore();        
}

void Update()
{
    if (Input.GetKeyDown(KeyCode.Space))
    {
        Save();            
    }
}

public void Save()
{
    score++;
    scoreTxt.text = "Score" + score;
    BinaryFormatter bf = new BinaryFormatter();
    FileStream file = File.Open(Application.persistentDataPath + "/scoreContainer.dat", FileMode.Create);

    ScoreContainer scoreContainer = new ScoreContainer();
    scoreContainer.score = score;
    bf.Serialize(file, scoreContainer);
    file.Close();
}

public void LoadScore()
{
    if(File.Exists(Application.persistentDataPath + "/scoreContainer.dat"))
    {
        BinaryFormatter bf = new BinaryFormatter();
        FileStream file = File.Open(Application.persistentDataPath + "/scoreContainer.dat", FileMode.Open);
        ScoreContainer scoreContainer = (ScoreContainer)bf.Deserialize(file);
        file.Close();
        score = scoreContainer.score;
        scoreTxt.text = "Score" + score;
    }
  }
}

[Serializable]
public class ScoreContainer
  {
    public int score;
  }

How can I change this so that each level has a separate highscore and all levels have a start score of 0?

Answer 1

You could have a separate file for each level and put the level number into the filename. For example, if your game has 200 levels, name the files "scoreContainer0.dat" to "scoreContainer199.dat".

When there is no score entry for a level yet, then that file won't exist yet. You can handle that case in LoadScore by setting score to 0 in that case.

string filename = Application.persistentDataPath + "/scoreContainer" + level + ".dat";
if(File.Exists(filename))
{
    BinaryFormatter bf = new BinaryFormatter();
    FileStream file = File.Open(filename, FileMode.Open);
    ScoreContainer scoreContainer = (ScoreContainer)bf.Deserialize(file);
    file.Close();
    score = scoreContainer.score;
    scoreTxt.text = "Score" + score;
} else {
    score = 0;
    scoreTxt.text = "Not played yet";
}

However, a cleaner solution might be to store the scores for all levels in one file. In that case I would use a C# integer array with each entry representing a score and the index being the level, or a Dictionary<int, int> with the first integer being the level number and the second integer being the score (the value-type of the dictionary might later receive an upgrade to a structure which contains more information about the state of the level). Either data type can be handled by the BinaryFormatter.

But this will require some more considerations regarding how you access the score values for levels in the rest of your code.